The Tissue Culture/Biomechanical Core (Core B) will provide critical support to Program Project Investigators while serving as a resource center and mechanism of integration between the five Projects. The Core facility will serve as a centralized resource unit providing laboratory personnel, expertise, and equipment to meet all human and murine endothelial cell needs for projects in the program. As all the five projects and Core D share a common theme of endothelial barrier regulation by the cytoskeleton, the major emphasis of this core will be to culture primary human pulmonary artery endothelial cells (HPAECs), human lung microvascular endothelial cells (HLMVECs), and isolate lung microvascular endothelial cells from various transgenic and genetically-altered murine models. The core has well trained personnel to process all the cell culture work and isolate lung microvascular ECs from murine models. The expertise and training we have developed during the last two cycles of this program project have defined the most effective mechanisms for culturing endothelial cells to assess permeability changes and/or pathologies. Another critical function of this Core will be facilitate experiments with cyclic stretch and atomic force microscopy (Core D) using dedicated instrumentation, computers and software systems. The close proximity of the tissue culture, biophysical and atomic force microscopy facilities will foster interaction between the investigators to develop and design experiments and interpret the reults. This will provide a unique environment where cell culture/biomechanical models and microscopic techniques will be refined and tailored to specific scientific needs of the projects. Thus, the tissue culture/biomechanical core facility is an integral component of the program project that ensures the most effective and economical use of the resources and expertise to meet the goals for each project.